Recent Posts

My first verified (imperative) program

13 minute read

One of the many exciting new features in the upcoming Lean 4.22 release is a preview of the new verification infrastructure for proving properties of imperat...

Freyd-Mitchell and Gabriel-Popescu Permalink

less than 1 minute read

Earlier this year, Jakob von Raumer, Paul Reichert and I finished a long project adding the Freyd-Mitchell and Gabriel-Popescu theorems to mathlib, Lean’s ma...

Lean has iterators now

1 minute read

Lean 4.22 (to be released in early August) will ship with the first version of the new iterators library, allowing for efficient streaming, combining and col...

The largest divisor

5 minute read

A few weeks ago I started the human-eval-lean project, an effort to collect hand-written solutions to the famous HumanEval (AI) programming benchmark, writte...